Randomised controlled trials (RCTs) of patients who received warfarin therapy and underwent an elective dental procedure were eligible if they compared continuance on the usual dose of warfarin with reduction or cessation of usual warfarin dose. Eligible studies had to assess at least one of arterial or venous thromboembolism or postoperative bleeding (major, minor or clinically significant non-major).
All of the included studies assessed patients who underwent dental extractions (single or multiple teeth). Most patients required anticoagulation therapy for prosthetic heart valves (range 45% to 100%); other indications included valvulopathy, deep vein thrombosis and atrial fibrillation. Mean international normalised ratio (INR) across studies of patients who continued warfarin was between 1.8 and 3.4. Warfarin was discontinued two days prior to the procedure in 40% of studies and 20% used a half dose of warfarin for two days prior to the procedure; other studies did not specify details of discontinuation of warfarin although one reported a target INR for control patients. All of the studies used cointerventions that varied between studies and in 60% of studies these differed between control and intervention groups (further details were reported in the review). All except one of the included studies was carried out in a hospital setting. Reported outcomes were non-major and minor bleeding. Where reported, follow-up duration was seven days in all studies.
Two reviewers independently selected studies for inclusion in the review.